6.1 Hyperglycemia in pregnancy

6.1.1 Risk factors³:

• BMI ≥23 kg/m2
• Age >25 years
• First degree relative with DM
• History of delivery of baby >9lb or LGA or bad obstetric history
• Previous history of GDM, HbA1c ≥5.7%, IGT or IFG
• Physical inactivity
• HTN or therapy for HTN, HDL <35 mg/dL and or TG >250 mg/dL, PCOS, acanthosis nigricans, history of CVD

See Chapter 2.

6.1.3 Preconception care¹

• Preconception HbA1c should be below 6.5%
• Women receiving non-insulin antihyperglycemic agents should shift to insulin before conception
• Review of medication list for potential harmful drugs like ACEI, ARBs or statins should be done.

Medical nutrition therapy

• MNT should be started soon after diagnosis of GDM preferably by dietitian and reviewed in each trimester.
• The aim is to achieve normoglycemia, adequate maternal weight gain, adequate fetal growth, prevention of ketosis.

Table 6.1 Recommended weight gain during pregnancy based on pre-pregnancy BMI³

Table 6.2 Daily calorie allocation according to pre-pregnancy weight³

Meal pattern

3 main meals and 3 snacks should be taken including 1 snack at bed time.

Recommended overall total caloric distribution³

• Carbohydrate: 33-40% with low glycemic index
• Protein: ~ 20%
• Fat: <40%, saturated fat <7% and transfat <1%
• Simple sugars should be avoided. Food containing complex carbohydrate is recommended
• High dietary fiber and whole grain containing foods should be encouraged
• Non-calorie sweeteners (aspartame) may be used safely
• Lean protein, oily fish and vegetable consumption should be increased
• Recommended daily requirement of iron- 30 mg, calcium- 1000 mg and folate- 0.6 mg

Physical activity¹

• Moderate exercise, aerobic, resistance or both are effective. Duration of exercise can be 20-50 minutes/day, 2-7 days/week of moderate intensity.
• While doing exercise excessive abdominal muscular contracture should be avoided.

Pharmacological management

Figure 6.1 Diabetes management during first and third trimester³

Figure 6.2 Diabetes management during second trimester³

Recommended insulins

• Recombinant human short and intermediate (NPH) acting insulin
• Rapid acting analogue aspart and lispro
• Long-acting analogue detemir
• Required initial daily dose is 0.2 to 0.5 unit/kg body weight. Obese women may need higher dose Treatment should be graded to reach the targets

Approach to start insulin

Step 1: Raised post meal blood glucose should be controlled by bolus insulin – either by regular/short acting human insulin or by short/ultra-short acting analogue with meal(s) and titrated frequently to reach the post-meal targets.

Step 2: High FPG should be controlled with intermediate acting human insulin (NPH) or basal analogue insulin in a lower dose then titrated to reach the target.³

• Only bolus insulin may be needed in some cases of GDM when FPG is well controlled
• Pre-mixed insulin is usually not preferred
• Non-insulin antihyperglycemic agents are not recommended

Target ¹

• Fasting blood glucose <5.3 mmol/L (95 mg/dL)
• 2-hour post-prandial glucose <6.7 mmol/L (120 mg/dL)

Glucose monitoring

• Every woman should be offered education and encouraged for self-monitoring of pre- and post-meal glucose at home, twice or thrice a week.
• HbA1c should be used as secondary measure of glycemic control, after blood glucose monitoring.

Management during labor⁴

• Hospital delivery is mandatory.
• Indications for C/S are the same for those with other women.
• Maternal glucose should be maintained between 4.0 to 7.0 mmol/L during labor.
• Most women who require <1.0 unit/kg/day insulin can simply be monitored without intravenous Insulin.
• If needed infusion of 5% Dextrose with short acting Insulin can be maintained but Glucose-Insulin infusion should be stopped immediately after delivery.
• Blood glucose of newborn should be seen by heel prick within half an hour.

6.1.5 Postpartum management³

• Mothers who were on low dose insulin (<0.5 unit/kg/day) can stop and monitor glucose levels. Mothers who were on insulin >1 unit/kg/day may reduce the dose to 50% and while those on 0.5-1 units need individualized clinical decision.
• If BG is normal, re-assessment should be done annually with 75-gm 2h OGTT or HbA1c. If prediabetes, should be put on MNT with standard protocol.
• After delivery at least 1 fasting and 1 post-meal PG before discharge should be measured in persons with GDM who were managed by MNT and FPG and PPG should be monitored for at least 24 hours who were managed with insulin. If blood glucose remains elevated, continued monitoring is warranted. If immediate post-delivery (1-3 days) BG is suggestive of DM, then should be confirmed by FPG (≥7 mmol/L) or post-prandial BG (≥11.1 mmol/L).
• As some case of GDM may represent preexisting undiagnosed type 2 diabetes and 50% women with GDM may develop type 2 DM within 5 to 10 years. Women with GDM (not requiring insulin after delivery) should be screened for diabetes 6 weeks post-partum (linked to child immunization) with 75g 2h OGTT using non-pregnant OGTT criteria.
• Contraception advice should be given. Low dose estrogen-progesterone can be offered for contraception. Progesterone only preparation increases risk of vascular complications.
• All types of insulins can be safely used in lactating women. Women with pre pregnancy diabetes who are breastfeeding should continue to avoid any drugs for the treatment of diabetes.
• All mothers with history of GDM should be counseled about screening for GDM during every subsequent pregnancy.